U.S. patent application number 16/749676 was filed with the patent office on 2020-08-20 for power supply and recharging assembly and method for an electric vehicle, and electric vehicle comprising the power supply and re.
The applicant listed for this patent is IVECO S.p.A.. Invention is credited to Alessandro Bernardini, Cristian Bertolotto, Giorgio Mantovani, Massimo Zappaterra.
Application Number | 20200262302 16/749676 |
Document ID | 20200262302 / US20200262302 |
Family ID | 1000004823452 |
Filed Date | 2020-08-20 |
Patent Application | download [pdf] |
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United States Patent
Application |
20200262302 |
Kind Code |
A1 |
Zappaterra; Massimo ; et
al. |
August 20, 2020 |
POWER SUPPLY AND RECHARGING ASSEMBLY AND METHOD FOR AN ELECTRIC
VEHICLE, AND ELECTRIC VEHICLE COMPRISING THE POWER SUPPLY AND
RECHARING ASSEMBLY
Abstract
A recharging method and assembly to charge an electric vehicle
comprising a battery pack including a plurality of storage
batteries having a same nominal charge voltage, the battery pack
being connectable to a recharging station adapted to provide a
recharging voltage, which his greater than said nominal charge
voltage. In an recharging mode of the battery pack, in which the
recharging voltage deliverable by the recharging station is smaller
than the sum of the nominal charge voltages of the plurality of
storage batteries, the storage batteries are connected in parallel
to one another, so as to recharge each battery with a recharging
voltage equal to the nominal charge voltage. In a different
recharging mode, in which the recharging voltage deliverable by the
recharging station is equal to o greater than the sum of the
nominal charge voltages of the plurality of storage batteries, the
storage batteries in series to one another, so as to recharge the
series of batteries with a recharging voltage greater than the
nominal charge voltage.
Inventors: |
Zappaterra; Massimo;
(Genova, IT) ; Bertolotto; Cristian; (Levanto
(SP), IT) ; Mantovani; Giorgio; (Genova, IT) ;
Bernardini; Alessandro; (Genova, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IVECO S.p.A. |
Torino |
|
IT |
|
|
Family ID: |
1000004823452 |
Appl. No.: |
16/749676 |
Filed: |
January 22, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B60L 53/30 20190201;
B60L 53/53 20190201; B60L 53/16 20190201 |
International
Class: |
B60L 53/16 20060101
B60L053/16; B60L 53/53 20060101 B60L053/53; B60L 53/30 20060101
B60L053/30 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 24, 2019 |
IT |
102019000001099 |
Claims
1. A method of recharging an electric vehicle (50) comprising a
battery pack (2) including a plurality of storage batteries (2a,
2b, . . . , 2i, 2j) having a same nominal charge voltage, the
battery pack (2) being connectable to a recharging station adapted
to provide a recharging voltage, the method comprising the steps
of: in a first recharging mode of the battery pack, in which the
recharging voltage supplied by the recharging station is equal to
said nominal charge voltage of the storage batteries, electrically
connecting the storage batteries to the recharging station in
parallel with each other, so as to recharge each storage battery
with a recharging voltage equal to the nominal charge voltage; and
in a second recharging mode of the battery pack, in which the
recharging voltage supplied by the recharging station is equal to
sum of the nominal charge voltages of the plurality of storage
batteries, electrically connecting the storage batteries in series
to each other, so as to recharge the series of storage batteries
with a recharging voltage equal to sum of the nominal charge
voltages.
2. The method according to claim 1, wherein the battery pack (2)
includes a first and a second battery (2a, 2b ) having a same
nominal charge voltage and each provided with a positive terminal
(2a', 2b', . . . , 2i', 2j') and a negative terminal (2a'', 2b'', .
. . , 2i'', 2j''); the first storage battery having the positive
terminal coupled to the first power supply terminal (4a) via a
first power supply switch (16a); and the second storage battery
having the negative terminal coupled to the power supply terminal
(4b) via a second power supply switch (16b); and in which the
negative terminal of the first storage battery is coupled to the
positive terminal of the second storage battery via a series switch
(20), wherein electrically connecting the storage batteries in
series comprises controlling the first and the second power supply
switches (16a, 16b) and said series switch (20) in conduction.
3. A power supply and recharging assembly for an electric vehicle
(50), comprising: a battery pack (2) including a plurality of
storage batteries (2a, 2b, . . . , 2i, 2j) having a nominal charge
voltage, the battery pack (2) being connectable to a recharging
station adapted to provide a recharging voltage; a power bus (6)
including a positive voltage line (6a) and a negative voltage line
(6b); and a connector (4) having a first and a second power supply
terminal (4a, 4b), configured to be connected to a recharging
station that is adapted to supply said connector (4) with a
recharging voltage; the storage batteries of said plurality of
storage batteries being coupled to the power bus, in a parallel
electrical configuration, via first switching means (12a, 12b, 14a,
14b); the storage batteries and the power bus being further coupled
to the connector (4) via second switching means (16a, 16b); and the
storage batteries being further coupled in series with each other
via third switching means (20), wherein, in a first recharging mode
of the battery pack, in which the recharging voltage supplied by
the recharging station is equal to said nominal charge voltage of
the storage batteries, the first, the second and the third
switching means are controllable to electrically connect said
storage batteries in parallel with each other, so as to recharge
each storage battery with a recharging voltage equal to the nominal
charge voltage; and in a second recharging mode of the battery
pack, in which the recharging voltage supplied by the recharging
station is equal to the sum of the nominal charge voltages of the
plurality of storage batteries, the first, the second and the third
switching means are controllable to electrically connect the
storage batteries in series with each other, so as to recharge the
series of storage batteries with a recharging voltage equal to the
sum of the nominal charge voltages.
4. The power supply and recharging assembly according to claim 3,
wherein said plurality of storage batteries includes a first and a
second storage battery (2a, 2b) having said nominal charge voltage
and each provided with a positive terminal (2a', 2b') and a
negative terminal (2a'', 2b''); wherein said first switching means
comprise: a first switch (12a) coupled between the positive
terminal (2a') of the first storage battery (2a) and the positive
voltage line (6a); a second switch (12b) connected between the
negative terminal (2a'') of the first storage battery (2a) and the
negative voltage line (6b); a third switch (14a) coupled between
the positive terminal (2b') of the second storage battery (2b) and
the positive voltage line (6a); and a fourth switch (14b) coupled
between the negative terminal (2b'') of the second storage battery
(2b) and a negative voltage line (6b); wherein said second
switching means comprise: a fifth switch (16a) coupled between the
first power supply terminal (4a) and the positive terminal (2a') of
the first storage battery (2a) and also coupled to the positive
voltage line (6a) via said first switch (12a); and a sixth switch
(16b) coupled between the second power supply terminal (4b) and the
negative terminal (2b'') of the second storage battery (2b) and
further coupled to the negative voltage line (6b); and wherein said
third switching means comprise a series switch (20) coupled between
the negative terminal (2a'') of the first storage battery (2a) and
the positive terminal (2b') of the second storage battery (2b), in
the first recharging mode of the battery pack (2), the first, the
second, the third, the fourth, the fifth and the sixth switches
(12a-16b) are controllable in conduction and said series switch
(20) is controllable in interdiction, to recharge the first and
second storage batteries with a recharging voltage equal to the
nominal charge voltage; and, in the second recharging mode of the
battery pack, the first, the second, the third and the fourth
switches (12a-14b) are controllable in interdiction, while said
fifth and sixth switches (16a, 16b) and said series switch (20) are
controllable in conducting, so as to recharge the series of storage
batteries with a recharging voltage higher than the nominal charge
voltage.
5. The power supply and recharging assembly according to claim 3,
further comprising an electronic control unit (51) operatively
coupled to the first, the second and the third switching means, and
configured to operate the first, the second and the third switching
means to implement the first recharging mode and, alternatively,
the second recharging mode of the battery pack.
6. The power supply and recharging assembly according to claim 5,
wherein the electronic control unit (51) is further configured to:
acquire a maximum value for the recharging voltage deliverable by
the recharging station; implement the first battery pack recharging
mode if the recharging voltage is lower than the sum of the nominal
charge voltages of the plurality of storage batteries; and
implement the second battery pack recharging mode if the recharging
voltage deliverable by the recharging station is equal to or
greater than the sum of the nominal charge voltages of the
plurality of storage batteries.
7. The power supply and recharging assembly according to claim 4,
wherein said series switch (20) has a first and a second conduction
terminal directly connected to the negative terminal of the first
storage battery and, respectively, to the positive terminal of the
second storage battery, said first conduction terminal of said
series switch (20) being coupled to the negative voltage line (6b)
via the first switch (12b), and said second conduction terminal of
said series switch (20) being coupled to the positive voltage line
(6a) via the third switch (14a).
8. The power supply and recharging assembly according to claim 7,
wherein: in a vehicle key-off operating mode, the first, the
second, the third, the fourth, the fifth and the sixth switches are
controllable in interdiction, so that the battery pack (2) is
disconnected from both the connector (4) and the power bus (6); and
in a power delivery mode, the first, the second, the third and the
fourth switches (12a-14b) are controllable in conduction state,
while the fifth and the sixth switches (16a, 16b) and said series
switch (20) are controllable tin interdiction state, so that the
battery pack (2) is connected to the power bus (6) to supply power
to the power bus.
9. The power supply and recharging assembly according to claim 3,
wherein said recharging voltage supplied by the recharging station
is between 800V and 1000V, said storage batteries being chosen so
that the sum of the respective nominal charge voltages is equal to
or less than said recharging voltage.
10. The power supply and recharging assembly according to claim 9,
wherein said plurality is two and the nominal charge voltage is
400V.
11. A battery-powered electric vehicle (50), including a power
supply and recharging assembly according to claim 1.
12. The electric vehicle (50) according to claim 11, further
comprising an electrical load (10) electrically connected to the
power supply and recharging assembly to receive a supply voltage
from the battery pack (2).
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority from Italian patent
application no. 102019000001099 filed on Jan. 24, 2019, the entire
disclosure of which is incorporated herein by reference.
STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT
[0002] Not Applicable
TECHNICAL FIELD
[0003] The invention relates to a power supply and recharging
assembly and method for an electric vehicle and to an electric
vehicle comprising the power supply and recharging assembly.
KNOWN STATE OF THE ART
[0004] As it is known, in an electric vehicle (EV), an electric
motor is the only source of energy used to drive the vehicle; in a
hybrid vehicle, the electric motor is an auxiliary source of energy
added to the internal combustion engine.
[0005] In an electric vehicle, the energy powering the electric
motor is typically stored in one or more storage batteries or
batteries. When the energy stored in the batteries decreases, they
can be charged by connecting to vehicle to an external power supply
source. Recharging stations (also known as "Electric Vehicle Supply
Equipment"--EVSE), which are used to this purpose, act as
interfaces between the vehicle and a power supply network, in order
to supply a charging or recharging current to the batteries. Known
recharging stations are configured to deliver recharging powers
whose maximum value depends on the voltage and current supported
both by the recharging stations themselves and by the electrical
components used to provide the service (cables, contacts, etc.).
More in particular, the maximum deliverable voltage depends on the
features, performances and/or building specifications of the
recharging station taken into account and on the maximum voltage
supported by the batteries of the electric vehicle being
charged.
[0006] Currently, recharging stations are available, which are
enabled to provide voltages up to 1000 V (high-power recharging
stations--HPC EVSE) and ensure small charging times. However, in
order to fully exploit the voltage provided by these stations, the
batteries mounted on board the vehicle must be designed to support
voltages with a corresponding value. Batteries capable of
supporting recharging voltages up to 800 V are available in the
market, but are very expensive and, therefore, are not widely
spread.
[0007] Therefore, there is a strong need to make use of high-power
recharging stations, in particular capable of delivering energy at
800 V, though using, at the same time, batteries that are available
in the market and are not too expensive.
[0008] The object of the invention is to fulfil the needs discussed
above.
SUMMARY OF THE INVENTION
[0009] The aforesaid object is reached by means of a power supply
and recharging assembly and method for an electric vehicle and of
an electric vehicle comprising the power supply and recharging
assembly, as set forth in the appended claims
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention will be best understood upon perusal of the
following detailed description of a preferred embodiment, which is
provided by way of non-limiting example, with reference to the
accompanying drawings, wherein:
[0011] FIG. 1 shows a recharging circuit for the storage batteries
of an electric vehicle according to an embodiment of the
invention;
[0012] FIGS. 2 and 3 show respective recharging circuits for the
storage batteries of an electric vehicle according to further
embodiments of the invention;
[0013] FIG. 4 schematically shows an electric vehicle provided with
the recharging circuit according to any one of the embodiments of
FIGS. 1-3.
DETAILED DESCRIPTION OF THE INVENTION
[0014] FIG. 1 schematically shows a recharging circuit 1 to charge
a battery pack 2 of an electric vehicle (which is schematically
shown in FIG. 4). The battery pack 2 is operatively coupled to an
electrical load 10 of the electric vehicle so as to supply the
electric energy needed for the operation of the electrical load 10.
The battery pack 2 includes a plurality of rechargeable storage
batteries. A connector 4 (which is also known as "charging inlet")
is fixed to the electric vehicle in a known manner and is provided
with a first and a second power supply pins 4a and 4b, which are
operatively coupled to the battery pack 2 and to a power bus 6
(Dc-link), which powers the electrical load 10. The power bus 6
comprises a positive voltage line (+) 6a and a negative voltage
line (-) 6b.
[0015] The electrical load 10 includes, in a per se known manner
which is not part of the subject-matter of the invention, at least
one inverter, which is coupled to the electric motor 10 so as to
generate a torque to move the vehicle. The electrical load 10 can
also include further components or systems of the electric vehicle,
which use, for their operation, the current flowing in the power
bus 6 (for example, the air conditioning system, the lighting
system, the infotainment system, etc.).
[0016] The battery pack 2 comprises, in the embodiment of FIG. 1, a
first and a second storage batteries 2a, 2b, each having the same
nominal charge voltage, which here, for example, is 400V. The first
and the second storage batteries 2a, 2b are, for example,
lithium-ion batteries or, in general, known electrochemical storage
batteries.
[0017] The first storage battery 2a has a positive terminal 2a'
(terminal +) coupled to the positive voltage line 6a and a negative
terminal 2a'' (terminal -) coupled to the negative voltage line
6b.
[0018] A switch 12a is interposed between the positive terminal 2a'
(terminal +) and the positive voltage line 6a. When the switch 12a
is in an open state, the positive terminal 2a' is electrically
disconnected from the positive voltage line 6a; when the switch 12a
is in a closed state, the positive terminal 2a' is electrically
connected to the positive voltage line 6a.
[0019] A switch 12b is interposed between the negative terminal
2a'' (terminal -) and the negative voltage line 6b.
[0020] When the switch 12b is in an open state, the negative
terminal 2a'' is electrically disconnected from the negative
voltage line 6b; when the switch 12b is in a closed state, the
negative terminal 2a'' is electrically connected to the negative
voltage line 6b.
[0021] Similarly, the second storage battery 2b has its own
positive terminal 2b' (terminal +) coupled to the positive voltage
line 6a and its own negative terminal 2b'' (terminal -) coupled to
the negative voltage line 6b.
[0022] A switch 14a is interposed between the positive terminal 2b'
(terminal +) and the positive voltage line 6a. When the switch 14a
is in an open state, the positive terminal 2b' is electrically
disconnected from the positive voltage line 6a; when the switch 14a
is in a closed state, the positive terminal 2b' is electrically
connected to the positive voltage line 6a.
[0023] A switch 14b is interposed between the negative terminal
2b'' (terminal -) and the negative voltage line 6b.
[0024] When the switch 14b is in an open state, the negative
terminal 2b'' is electrically disconnected from the negative
voltage line 6b; when the switch 14b is in a closed state, the
negative terminal 2b'' is electrically connected to the negative
voltage line 6b.
[0025] In FIG. 1, reference numeral 15 indicates an electric node
between the positive terminal 2a' of the first storage battery 2a
and the switch 12a (in particular, the node 15 coincides with the
positive terminal 2a'). Furthermore, it is shown a further electric
node 17 between the negative terminal 2b'' of the second storage
battery 2b and the switch 14b (in particular, the node 17 coincides
with the negative terminal 2b'').
[0026] The first power supply pin 4a of the charging inlet 4 is
coupled, through a switch 16a, to the node 15. The second power
supply pin 4b is coupled, through a switch 16b, to the node 17.
[0027] The switches 16a and 16b can be switched to an open state
and to a closed state so as to electrically disconnect and connect,
respectively, the power supply pins 4a, 4b from/to the nodes 15,
17.
[0028] Therefore, according to the operating diagram suggested
herein, the first power supply pin 4a of the charging inlet 4 is
coupled to the positive power supply line 6a by means of the switch
12a and the second power supply pin 4b of the charging inlet 4 is
coupled to the negative power supply line 6b by means of the switch
14b.
[0029] According to an aspect of the invention, the negative
terminal 2a'' of the first storage battery 2a is coupled to the
positive terminal 2b' of the second storage battery 2b by means of
a switch 20. The switch 20 can be switched to an open state so as
to electrically disconnect the negative terminal 2a'' from the
positive terminal 2b' and to a closed state so as to electrically
connect the negative terminal 2a'' to the positive terminal
2b'.
[0030] As explained more in detail below, the switch 20 has the
function, in an operating condition which is better discussed
hereinafter, of electrically connecting the first and the second
storage batteries 2a, 2b to one another in series.
[0031] In a non-limiting embodiment, the switches 12a, 12b, 14a,
14b, 16a, 16b and 20 are contactors, namely electric-mechanical
devices, which are not manually operated and are adapted to stand
currents in high-power conditions (in this case, amounting to
hundreds of Volts, in particular up to 800 V). Alternatively, the
switches 12a, 12b, 14a, 14b, 16a, 16b and 20 can be solid-state
devices, chosen depending on the needs.
[0032] The switches 12a, 12b, 14a, 14b, 16a, 16b and 20 are
operatively coupled to an electronic control unit (shown in FIG. 4
with reference number 51), which is configured to switch the
switches 12a, 12b, 14a, 14b, 16a, 16b and 20 to an open and closed
state in order to implement a plurality of operating modes
described hereinafter.
[0033] In detail, the electronic control unit 51 is configured to
control the switches 12a, 12b, 14a, 14b, 16a, 16b and 20 so as to
implement a plurality of operating modes of the recharging circuit
1, among which there are, in particular: a rest mode (or "key-off"
mode), a power supply mode, a first recharging mode and a second
recharging mode.
[0034] In the key-off mode, the electric vehicle is not powered by
means of the battery pack 2 and, at the same time, the battery pack
2 is not being charged (for example, when the electric vehicle is
parked).
[0035] In the power supply mode, the electrical load 10 is powered
by means of the battery pack 2 (for example, during the drive).
[0036] In the first and the second recharging modes, the batteries
are charged using different values of recharging voltage.
[0037] The electronic control unit 51 can be the electronic control
unit of the electric vehicle, properly configured, via software, to
implement one or more of the aforesaid operating modes (in
particular, the first recharging mode and the second recharging
mode); alternatively, the electronic control unit 51 can be a
further additional control unit beside the electronic control unit
of the electric vehicle or a generic controller, properly
configured and designed to implement one or more of the aforesaid
operating modes (in particular, the first recharging mode and the
second recharging mode).
[0038] More in detail, in the key-off mode, the switches 12a, 12b,
14a, 14b, 16a, 16b and, optionally, the switch 20 are controlled by
the electronic control unit 51 so as to switch to an open
state.
[0039] The following table schematically shows the state of the
aforesaid switches in the key-off mode:
TABLE-US-00001 Switch 12a OPEN Switch 12b OPEN Switch 14a OPEN
Switch 14b OPEN Switch 16a OPEN Switch 16b OPEN Switch 20 OPEN
[0040] Therefore, the batteries 2a and 2b are electrically
disconnected both from the charging inlet 4 and from the power bus
6.
[0041] In the power supply mode, the switches 16a, 16b and 20 are
controlled by the electronic control unit 51 so as to switch to an
open state, whereas the switches 12a, 12b, 14a and 14b are
controlled by the electronic control unit 51 so as to switch to a
closed state.
[0042] The following table schematically shows the state of the
aforesaid switches in the power supply mode:
TABLE-US-00002 Switch 12a CLOSED Switch 12b CLOSED Switch 14a
CLOSED Switch 14b CLOSED Switch 16a OPEN Switch 16b OPEN Switch 20
OPEN
[0043] As a consequence, the batteries 2a, 2b are electrically
connected in parallel to the power bus 6 and the electrical load 10
is powered by means of the voltage provided by the storage
batteries 2a, 2b. As already mentioned above, in this embodiment,
each storage battery 2a, 2b provides the power bus 6 with a nominal
voltage of approximately 400V. Furthermore, the battery pack 2 is
electrically disconnected from the charging inlet 4.
[0044] In the first recharging mode, the switch 20 is controlled by
the electronic control unit 51 so as to switch to an open state,
whereas the switches 16a, 16b, 12a, 12b, 14a and 14b are controlled
by the electronic control unit 51 so as to switch to a closed
state.
[0045] The following table schematically shows the state of the
aforesaid switches in the first recharging mode:
TABLE-US-00003 Switch 12a CLOSED Switch 12b CLOSED Switch 14a
CLOSED Switch 14b CLOSED Switch 16a CLOSED Switch 16b CLOSED Switch
20 OPEN
[0046] As a consequence, the first and the second storage batteries
2a, 2b are electrically connected to one another in parallel and
are charged by means of the power supply voltage provided by the
charging station through the charging inlet 4. In a known manner,
during the first recharging mode, the electric vehicle communicates
to the recharging station the maximum voltage limit supported by
the battery pack 2, so as to protect the battery pack 2 from
overvoltages. In this way, even though the known recharging station
can supply voltages up to 1000V (more commonly 800V), the battery
pack 2 is charged at the nominal charge voltage of the storage
batteries 2a, 2b, without damages. Since the power bus 6 is
powered, the electrical load 10 can be selectively disconnected
from the power bus 6.
[0047] In the second recharging mode, the switches 16a, 16b and 20
are controlled by the electronic control unit 51 so as to switch to
a closed state, whereas the switches 12a, 12b, 14a and 14b are
controlled by the electronic control unit 51 so as to switch to an
open state.
[0048] The following table schematically shows the state of the
aforesaid switches in the second recharging mode:
TABLE-US-00004 Switch 12a OPEN Switch 12b OPEN Switch 14a OPEN
Switch 14b OPEN Switch 16a CLOSED Switch 16b CLOSED Switch 20
CLOSED
[0049] As a consequence, the first and the second storage batteries
2a, 2b are electrically connected to one another in series and are
charged by means of the power supply voltage provided by the
charging station through the charging inlet 4.
[0050] During the first and the second recharging modes, the
electric vehicle communicates to the recharging station, through
the battery management system--BMS, the maximum voltage supported
by the battery pack 2. The BMS communicates with the recharging
station through high-level communication (e.g. PLC or WiFi or
another communication mode), according to the IEC61851 and ISO
15118 standards. The BMS is also interfaced with the electronic
control unit 51 and serves as communication interface between the
latter and the recharging station.
[0051] As an alternative or in addition to the BMS, the VMU can
carry out this interface function.
[0052] Since the storage batteries 2a, 2b are electrically
connected to one another in series, the maximum voltage supported
by the battery pack 2, in the second recharging mode, is greater
than each one of the nominal voltages of the storage batteries 2a,
2b; in particular, the maximum voltage supported by the battery
pack 2 is the result of the sum of the nominal charge voltages of
the storage batteries 2a, 2b (hence, in this example, the maximum
voltage supported by the battery pack 2 is 800V). In this way, the
potentialities of the recharging station (for instance, power
delivered) can be exploited to the utmost, charging the battery
pack 2 at a voltage that is greater than the one of the recharging
mode described above, thus reducing charging times.
[0053] Based on the information received from the BMS, depending on
the voltage that can be delivered by the recharging station, the
electronic control unit 51 controls the state of the switches 12a,
12b, 14a, 14b, 16a, 16b and 20, implementing one of the recharging
modes of the battery pack 2 described above based on the electric
features of the recharging station with which the recharging
circuit 1 is interfaced. For example, the switches are controlled
in accordance with the first recharging mode (batteries 2a, 2b in
parallel) in order to charge the batteries 2a, 2b at 400V when the
recharging station supports a maximum voltage of 400V, or in
accordance with the second recharging mode (batteries 2a, 2b in
series) in order to charge them at 800V when the recharging station
supports a maximum voltage of 800V.
[0054] According to a further embodiment, which is shown in FIG. 2,
the battery pack 2 comprises a plurality of storage batteries 2a,
2b, . . . , 2i, 2j. The elements of FIG. 2 that are the same as the
ones of FIG. 1 are not further discussed and are indicated with the
same reference numbers.
[0055] The nominal charge voltage of the storage batteries 2a-2j is
chosen during the design phase based on the maximum voltage that
can be delivered by the existing recharging stations and on the
number of storage batteries to be installed on board the vehicle.
In particular, the storage batteries 2a-2j have a same nominal
charge voltage, which is chosen in such a way that the sum of the
nominal charge voltages of the storage batteries 2a-2j (namely, the
charge voltage at the ends of the battery pack 2 when the storage
batteries 2a-2j are arranged in series with one another) is equal
to or smaller than the voltage that can be delivered by the
recharging station. In the diagram of FIG. 2, assuming--by way of
example--that there is a total number of storage batteries 2a-2j of
four and that the maximum voltage that can be delivered by the
recharging station is 800V, each storage battery 2a-2j is chosen so
as to have a nominal charge voltage of 200V.
[0056] In order to create the electric series connection of the
storage batteries 2a-2j, there are switches 20a, 20i and 20j that
electrically connect the opposite terminals of successive storage
batteries of the electric series, similarly to what described above
with reference to the switch 20, so as to obtain a series
connection of all the storage batteries 2a-2j of the battery pack
2.
[0057] Furthermore, the switches 22a, 22b, 24a and 24b are shown,
which have a function that is similar to the one described in FIG.
1 with reference to the switches 12a, 12b, 14a and 14b,
respectively.
[0058] As a consequence, when the storage batteries 2a-2j are
charged in accordance with the second recharging mode described
above, the storage batteries 2a-2j are arranged in series with one
another closing the switches 20a, . . . , 20i, 20j; therefore, they
can be charged exploiting the maximum voltage delivered by the
recharging station.
[0059] According to a further embodiment, which is shown in FIG. 3,
the battery pack 2 of FIG. 1 is repeated k times. Therefore, with
reference to FIG. 3, there are a plurality k of battery packs 2, .
. . , k, with k being chosen based on the needs during the design
phase. Each battery pack 2-k comprises a number of storage
batteries chosen depending on what already discussed above with
reference to FIGS. 1 and 2. The battery packs 2-k are electrically
connected to the power bus 6 in parallel to one another and charged
at the same time.
[0060] FIG. 4 schematically shows an electric vehicle 50 including:
the charging inlet 4; the recharging circuit 1; the battery pack 2
(or a plurality of battery packs 2-k); the electronic control unit
51; and the electrical load 10. The electronic control unit 51, as
already mentioned above, is operatively coupled to the switches
12a, 12b, 14a, 14b, 16a, 16b so as to implement the operating modes
discussed above and, furthermore, is operatively coupled to the
electrical load 10, for example in order to inhibit the drive of
the electric vehicle stopping the operation of the electric motor
during the first recharging mode; however, during the first
recharging mode, the electronic control unit 51 can be configured
to enable the operation of the air conditioning system and/or of
the lighting system or of other systems or components of the
electric vehicle other than the motor.
[0061] Owing to the above, the advantages of the subject-matter of
the invention are evident.
[0062] In particular, the invention allows for a reduction of the
time needed to charge the battery pack of the electric vehicle,
with the possibility of adjusting to the features and performances
of different recharging stations with which the electric vehicle
can be interfaced during the use, using low-cost components. In
particular, it is possible to use batteries with a nominal charge
voltage of a few or some hundreds of Volts (for example, up to
400V), which can easily be found in the market and are relatively
cheap, and, at the same time, it is possible to fully exploit the
power that can be delivered by high-power recharging stations (HPC
EVSE), which are designed to supply power with voltages up to
800-1000V.
[0063] Finally, the subject-matter of the invention can be
subjected to changes and variants, which, though, do not go beyond
the scope of protection set forth in the appended claims.
[0064] For example, one or more of the switches 12a, 12b, 14a, 14b,
16a, 16b and 20 can be arranged in a different way than the one
shown in the figures, provided that they implement, when they are
controlled accordingly, the operating modes provided for by the
invention (in particular, the shift from the first to the second
recharging mode depending on the voltage than can be delivered by
the recharging station).
* * * * *